It is often desirable and frequently necessary to sample or test a portion of tissue from humans and other animals, particularly in the diagnosis and treatment of patients with cancerous tumors, pre-malignant conditions and other diseases or disorders. Typically, in the case of cancer, when the physician establishes by means of procedures such as palpation, x-ray or ultra sound imaging that suspicious circumstances exist, a biopsy is performed to determine whether the cells are cancerous. Biopsy may be done by an open or percutaneous technique. Open biopsy removes the entire mass (excisional biopsy) or a part of the mass (incisional biopsy). Percutaneous biopsy on the other hand is usually done with a needle-like instrument and may be either a fine needle aspiration (FNA) or a core biopsy. In FNA biopsy, individual cells or clusters of cells are obtained for cytologic examination and may be prepared such as in a Papanicolaou smear. In core biopsy, as the term suggests, a core or fragment of tissue is obtained for histologic examination which may be done via a frozen section or paraffin section.
The type of biopsy utilized depends in large part on circumstances present with respect to the patient and no single procedure is ideal for all cases. However, core biopsy is extremely useful in a number of conditions and is being used more frequently by the medical profession.
To arrive at a definitive tissue diagnosis, intact tissue is needed from an organ or lesion within the body. In most instances, only part of the organ or lesion need be sampled. However, the portions of tissue obtained must be representative of the organ or lesion as a whole. In the past, to obtain tissue from organs or lesions within the body, surgery had to be performed to locate, identify and remove the tissue. With the advent of medical imaging equipment (x-rays and fluoroscopy, computed tomography, ultrasound, nuclear medicine, and magnetic resonance imaging) it became possible to identify small abnormalities even deep within the body. However, definitive tissue characterization still requires obtaining adequate tissue samples to characterize the histology of the organ or lesion.
For example, mammography can identify non-palpable (not perceptible by touch) breast abnormalities earlier than they can be diagnosed by physical examination. Most non-palpable breast abnormalities are benign; some of them are malignant. When breast cancer is diagnosed before it becomes palpable, breast cancer mortality can be reduced. However, it is often difficult to determine if pre-palpable breast abnormalities are malignant, as some benign lesions have mammographic features which mimic malignant lesions and some malignant lesions have mammographic features which mimic benign lesions. Thus, mammography has its limitations. To reach a definitive diagnosis, tissue from within the breast must be removed and examined under a microscope. Prior to the late 1980's, reaching a definitive tissue diagnosis for non-palpable breast disease required a mammographically guided localization, either with a wire device, visible dye, or carbon particles, followed by an open, surgical biopsy utilizing one of these guidance methods to lead the surgeon to the non-palpable lesion within the breast.
The open method is illustrated in FIGS. 1A through 1E. FIG. 1A depicts an accurately localized lesion. A lesion 5 is located per one of the aforementioned visualization means. The breast 1 is pierced with a localization wire 3 with the intention of positioning the large diameter section of the wire through the center of the lesion to act as a temporary marker. In a subsequent procedure, tissue is removed around the area marked by the localization wire. The tissue is then prepared and sectioned for evaluation. Open surgical breast biopsies have many drawbacks. They can be disfiguring, expensive (in terms of direct costs to the patient and indirect costs to society from the patient being away from work), and are imperfect (the error rate for surgical biopsy has been reported to be from 2% to 22%). FIG. 1B illustrates a localization wire 3 incorrectly placed by a radiologist. FIG. 1C illustrates a properly placed localization wire 3 but poor tissue selection 7 by the surgeon in which the lesion 5 was not harvested. FIGS. 1D and 1E illustrate a properly harvested lesion 9 with the wrong section prepared for analysis. As shown, the lesion 5 is included in the harvested tissue sample 9. However, in sectioning the tissue sample 9 along A--A and B--B for examination, the lesion 5 was missed. Any of these errors will lead to an incorrect diagnosis of the lesion. Open surgical biopsies also carry a small mortality risk (the risk of anesthesia) and a moderate morbidity rate (including bleeding, infection, and fracture or migration of the localizing wire) In cases where multiple lesions are present in the breast, a surgeon is reluctant to biopsy each lesion due to the large tissue mass that must be extracted with each lesion. The most convenient lesion is taken which results in an incomplete diagnosis. Finally, surgical breast biopsies are extremely common. In the United States, alone, it is estimated that open, surgical breast biopsies are performed on over 500,000 women annually. A less invasive alternative has long been sought.
In the fall of 1988, two different stereotactic guidance systems were modified to allow the guiding portion of each system to accommodate spring powered devices such as the Biopty.RTM. (Bard Radiology) gun. In the summer of 1989, free-hand ultrasound guidance techniques were developed to guide the Biopty.RTM. gun to breast lesions seen by ultrasound. With the introduction of stereotactic and ultrasound guided percutaneous breast biopsies, an alternative to open, surgical breast biopsy was at hand.
With image guided percutaneous core breast biopsy, it may be possible to greatly reduce the number of open, surgical breast biopsies performed. However, there are limiting factors with image guided breast biopsies. The current generation of biopsy guns acquire specimens slowly. The placement of the needle of the gun has to be made very accurately because only one small core is obtained per insertion at any one location. To sample a lesion thoroughly, many separate insertions must be made. Finally, there is no means to completely excise a small lesion at the time of the initial diagnostic biopsy.
Stereotactic and ultrasound guidance systems have improved continuously since their introduction. Guidance systems are now more accurate, user friendly, and rapid than when they were introduced. On the other hand, automated biopsy gun systems have not evolved much since their initial introduction.
Many biopsy procedures now require a plurality of samples to be taken. For example, up to six or more samples of tissue are often required when testing the tissues of the breast, prostate gland and other body organs. In order to take multiple tissue samples using the prior art biopsy devices, each time a sample is taken, the device must be removed, and a new puncturing of the breast or organ made. This action is tedious and time consuming. Moreover, multiple manual penetrations of the organ are typically somewhat painful, and such penetrations are subject to bleeding and infection.
Multiple samples may be obtained with a device disclosed in U.S. Pat. No. 4,976,269 (Mehl). The Mehl device allows the cannula to remain in the body, but the stylette with its tissue receiving notch must be manually withdrawn from the tissue, organ, and cannula so that the test sample can be removed, a tedious and time consuming process. Samples may be compromised through prolonged sliding contact with the inside surface of the cannula during withdrawal of the stylet. To obtain a second tissue sample, the stylet is manually reinserted into the biopsy device, through the cannula, and into the organ and tissue to be sampled.
Another significant drawback of the prior art is that the stylets bearing the tissue samples must be manually handled. This exposes those persons handling the stylets to danger of infection, e.g., HIV infection. Additionally, with present devices, the stylets and samples are handled on an individual basis. The tissue samples are often damaged or destroyed due to improper handling. There is also the possibility of loss or mislabeling of the samples.
A need thus exists for a biopsy device which can take a plurality of tissue samples painlessly, in rapid sequence, minimizing handling in a way that protects the handling personnel and the tissue samples.
The True Cut.RTM. needle (Travenol Laboratories) optimally allows a roughly cylindrical shaped sample of tissue, termed a "core," to be obtained from a pointed, side cutting device, percutaneously. The True Cut.RTM. needle as shown in FIG. 1F, comprises a pointed inner stylette 11 with a side facing notch 13 to receive tissue near its pointed end (tissue receiving notch) and an outer, sharpened sliding cannula 15. The operational sequence of the True Cut.RTM. needle biopsy system is shown schematically in FIG. 1G. Once the lesion is targeted, the inner stylette 11 is thrust into the organ or lesion of interest. Tissue passively prolapses into the side facing notch 13 and the outer cannula 15 is rapidly advanced, thereby cutting off the sample of tissue contained within the notch. The entire needle system is withdrawn out of the body and the sample is manually extracted from the receiving notch 13 and handled for processing. Each specimen requires reassembly of the needle system, relocation of the lesion, and repositioning of the device.
The True Cut.RTM. needle works within a certain set a operating parameters, but is rough on organs and lesions, often only obtaining small fragments of tissue, and is quite operator dependent--some individuals are good at operating the device and some are not. FIG. 1H shows tissue 17 optimally prolapsed into the receiving chamber 13. FIG. 1I and 1J illustrate other common occurrences when using the True Cut.RTM. needle system. In FIG. 1I, tissue 17 is partially prolapsed into the receiving notch 13. Partial prolapse results in insufficient sampling, and may be caused by insufficient dwell time before cutting, by a natural bias of the tissue to migrate away from the receiving notch when it is pierced, or by forced migration of the tissue during forward movement of the cutter 1s. FIG. 1J illustrates bleeding at a preceding biopsy site that has formed into a clot 19. Tissue 17 is not allowed into the tissue receiving notch 13 which is occupied by clot 19. In this situation a clot sample is obtained instead of lesion or normal tissue.
A variety of biopsy needles and guns have been described and used for obtaining tissue specimens. These guns are an improvement over manual use of the True Cut.RTM. needle. One such biopsy gun currently used is described in U.S. Pat. No. Re. 34,056, entitled "TISSUE SAMPLING DEVICE", issued to Lindgren et al. Additional examples of biopsy gun devices are disclosed in U.S. Pat. Nos. 4,600,014 and 4,958,625. The Lindgren Automatic Core Biopsy Device (ACBD) is an instrument which propels a needle set with considerable force and speed in order to pierce the tumor mass and collect the tissue sample. The ACBD has allowed physicians to accurately test tissue masses in the early stages of growth and has contributed to the medical trend of early diagnosis and successful treatment of cancer. The ACBD allows a biopsy to be performed on tumor masses as small as two millimeters in diameter. This procedure is performed under ultrasound or X-ray guidance. Tumors of this size cannot be biopsied reliably by hand since the tumor is about the same size as the biopsy needle. Manual attempts at biopsy pushes the tumor away without piercing the mass. Automatic puncture devices accelerate the needle at such a velocity that even a small tumor can be pierced. Typically, Automatic Core Biopsy Devices use the True Cut.RTM. needle set design. The stylet is advanced into the tissue under spring power followed by the cannula which cuts and traps the tissue sample in the notch of the stylet as previously discussed. The True Cut.RTM. needle yields a core sample which is semi-circular in cross-section with a length determined by the stroke of the ACBD. The most common True Cut.RTM. needle size used by ACBD's is 14 gauge. The use of 14 gauge needles is a compromise between the physician's desire to use the smallest, least invasive, needle gage and the pathologist's needs for as large a tissue sample as possible to minimize false-positive and false-negative diagnosis. This compromise in needle size leads the physician to obtain multiple core samples from the biopsy site to allow the pathologist sufficient tissue for an accurate diagnosis.
The Automatic Core Biopsy Devices are able to obtain tissue from within the body with less trauma, more consistently, and in larger quantities than the manually operated True Cut.RTM. needle. However, they do have disadvantages. For example, they are typically spring powered devices and must be manually cocked with a plunger bar. Such "cocking" of the gun requires considerable force and the gun must be cocked for each biopsy cut. When actuated, the springs provided in the gun accelerate the needles until a mechanical stop position is reached creating a loud snapping noise and jerking motion which is a problem both to the physician and the patient.
Further short comings of the ACBD's include: 1) Absence of a mechanism for capturing tissue in the tissue receiving notch under varying types of tissue consistency (from soft to hard) prior to the action of the outer cutting cannula. 2) No means is provided for systematic change in position of the tissue receptacle about the long axis of the needle system. If the ACBD is held in the same orientation or is mounted in a holder, the cutting action is always in the same place, i.e., the True Cut.RTM. type needle only cuts from a 7:00 o'clock position to a 5:00 o'clock position each time it is operated. 3) They do not provide a means for systematic change in the position of the tissue receiving notch along the long axis of the stylette. 4) They do not provide for a means to allow the removal of a volume of tissue about the long axis of the needle that is larger than the diameter of the True Cut.RTM. type needle. 5) They do not provide for a means to remove a volume of tissue along the long axis of the needle that is larger in volume than the tissue receptacle of the True Cut.RTM. type needle. 6) They do not provide for a means to remove more than one core of tissue per entry into the body, organ, and lesion. With existing technology, each entry retrieves only one core sample. To obtain another core, another entry into the lesion is required. Consequently, the process of obtaining sufficient tissue to characterize heterogeneous tissue is very time consuming and tedious. With the passage of time, patient fatigue leads to patient motion and accuracy can fall. 7) They do not provide for a means to code or decode where, within the organ or lesion, the core samples originated to allow later reconstruction of the histology of the entire volume sampled. 8) They do not provide a means which allows complete removal of small lesions. Various attempts to overcome one or more of the disadvantages of the ACBD have been made.
U.S. Pat. No. 5,183,052, entitled "AUTOMATIC BIOPSY INSTRUMENT WITH CUTTING CANNULA", issued to Terwilliger describes a biopsy instrument having a stylet and a cannula wherein the instrument urges the cannula past the stylet in order to collect a tissue sample and simultaneously causes a vacuum to be communicated to the cannula in order to assist the collection of the tissue sample by the cannula.
U.S. Pat. No. 5,183,054, entitled "ACTUATED BIOPSY CUTTING NEEDLE WITH REMOVABLE STYLET", issued to Burkholder et al., discloses a biopsy device having a tubular cannula through which a stylet having a stylet cavity near the distal end is placed. The stylet is removable from the cannula and removed from the biopsy device through the housing so that the tissue sample obtained by the biopsy device may be manually retrieved while the cannula remains in place within the patient, near the area being sampled. Thereafter, the stylet may be reinserted through the housing and cannula into the patient's tissue where additional tissue samples may be obtained. In this way, trauma to the tissue that ordinarily occurs upon reinsertion of the cannula and stylet is minimized.
U.S. Pat. No. 5,234,000, entitled "AUTOMATIC BIOPSY DEVICE HOUSING A PLURALITY OF STYLETS", issued to Hakky et al. describes a biopsy device for taking a plurality of samples of tissue from a living being. The device comprises a housing having a portion arranged to be held by a person using the device, a cannula having a proximal portion and a distal portion and being coupled to the housing. A plurality of stylets are located in the housing, with each of the stylets having a proximal end, a distal end, and a tissue receiving notch located adjacent the distal end. Each stylet is individually propelled through the cannula into the body so that a portion of the tissue prolapses into the notch. The Burkholder et al. and Hakky et al. devices share all of the disadvantages of True Cut.RTM. type devices described previously with the exception of being limited to acquiring a single sample. In addition, transportation of samples by withdrawing stylettes from the instrument may compromise quality of the specimens through prolonged contact with the inside surface of the cannula.
U.S. Pat. No. 5,195,533, entitled "BIOPSY NEEDLE INSTRUMENT FOR STORING MULTIPLE SPECIMENS", issued to Chin et al. describes a biopsy needle instrument which includes a housing, an axially elongated stylet extending from the housing and a cannula coaxially extending from the housing and disposed about the stylet means. The stylet and cannula can move relative to each other and to the housing between extended and retracted positions. The stylet and cannula define, during a given operation, a specimen of a predetermined specimen axial length. The stylet includes means coacting with the cannula for storing multiple, sequentially obtained specimens within the instrument. While multiple samples may be acquired with this device, there is no provision for separating the samples from each other or maintaining the integrity of the individual samples. In addition, the volume of tissue collected per entry into the body cannot exceed the capacity of the receiving notch.
U.S. Pat. No. 4,651,753, entitled "ENDOSCOPIC MULTIPLE BIOPSY INSTRUMENT", issued to Lifton describes a biopsy instrument for use with an endoscope which includes a rigid cylindrical end attached to the distal end of a flexible arrangement of tubes. The rigid end comprises a cylindrical body having a cavity therein. The cavity extends towards the distal end of the body and is of size sufficient to hold plural samples therein. Inside the cylindrical body is a passageway which serves as a conduit for aspiration of tissue into the cavity and cylindrical body and a knife for cutting the tissue. Furthermore, a plunger is arranged coaxially with the knife for pushing individual biopsy samples of a plurality into the distal end cavity of the cylindrical body. This device is clearly for endoscopic use and would be inappropriate for use in obtaining samples from a breast or organ interior. Although this device employs an active means to urge tissue into the receiving notch, it bears the same deficiencies as the Chin device. The volume of tissue collected per bodily insertion cannot exceed the collection chamber volume, the origin of the samples cannot be differentiated, and the samples recovered must be manually handled for preparation.
The requirements of the physician and the pathologist dictate the need for an alternative approach in the function and design of the conventional ACBD, needle sets and other biopsy devices. The ideal product would allow for collection of larger tissue volume through a small opening, reliable active tissue capture mechanism, more accurate control of the location from which samples are acquired, ability to acquire multiple samples from the biopsy site without having to reinsert the biopsy needle, less traumatic transportation and storage of samples with minimum handling, and correlation of sample storage to harvest site.